Abstract:
Microbes with the nitrogenase enzyme on mosses and soils, particularly the cyanobacteria Nostoc, were examined to investigate the extent and magnitude of the nitrogen fixation process. Sample cores from continuous cover of Nostoc in the Garwood Valley and Cape Royds were collected and subjected to various experimental conditions and using the acetylene reduction technique (to determine nitrogen ... fixation) and gas chromatography (to measure ethylene gas) the nitrogen fixation process was determined from diverse habitats. Core samples were incubated in 500ml jars containing 1% acetylene gas for no longer than 12hours in sub, shade or dark conditions and gas samples were removed periodically and ethylene was determined. In experiments, Nostoc was subjected to 5 cycles of oscillating environmental conditions to determine quantitative fixation levels in Nostoc at different moisture levels and the effect of oscillating environmental cycles on nitrogen fixation. Fresh, dry and ash free sample weights and nitrogen content were determined. Temperature and pH measurements of soils, waters and plants were made at the study site. The effects of amendments on fixation rates was determined by measuring fixation on samples subjected to phosphate, trace elements, chemical residue of a smoke bomb, urine, trampling and cover with soil 1cm deep.

Description:
The algae culture collection is stored in a -20 freezer at the Molecular Laboratory and Allan Herbarium at Landcare Research, New Zealand. It is unknown what cultures are still viable and what species are available. The lab has PC2 containment and transfers have to be done according to Ministry of Agriculture and Fisheries (MAF) protocol. Contact Phil Novis: NovisP@landcareresearch.co.nz for more information.

Quality
Some cultures may still exist and are held by Landcare Research, New Zealand. The quality of these cultures is unknown. Field notebooks, diaries, etc are retained by the investigator.

Access Constraints
If the cultures are wanted to be transeferred from Landcare Research, the receiving lab needs to have the necessary containment certification (i.e. PC2 containment) and transfers have to be done according to MAF protocol. Otherwise the work needs to be done in the Landcare Research Molecular lab.